It has been shown that antihemolytic effect of trifluoroperazine is realized directly at the stage of hyperosmotic stress during cell transfer to 4.0 M NaCl and is not the result of preliminary cell treatment by this amphypathic compound. The value of protecting effect of trifluoroperazine is determined by preliminary RBS dehydration condition. Cell treatment by hemin, modifying cytoskeleton and membrane, significantly affects cell sensitivity to hyperosmotic stress both in the presence of trifluoroperazine and without the latter.